#line 1 "template/template.hpp"
#include <bits/stdc++.h>

#define rep(i, a, n) for (int i = (int)(a); i < (int)(n); i++)
#define rrep(i, a, n) for (int i = ((int)(n)-1); i >= (int)(a); i--)
#define Rep(i, a, n) for (i64 i = (i64)(a); i < (i64)(n); i++)
#define RRep(i, a, n) for (i64 i = ((i64)(n)-i64(1)); i >= (i64)(a); i--)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()

#line 2 "template/debug_template.hpp"

#line 4 "template/debug_template.hpp"

namespace ebi {

#ifdef LOCAL
#define debug(...)                                                      \
    std::cerr << "LINE: " << __LINE__ << "  [" << #__VA_ARGS__ << "]:", \
        debug_out(__VA_ARGS__)
#else
#define debug(...)
#endif

void debug_out() {
    std::cerr << std::endl;
}

template <typename Head, typename... Tail> void debug_out(Head h, Tail... t) {
    std::cerr << " " << h;
    if (sizeof...(t) > 0) std::cerr << " :";
    debug_out(t...);
}

}  // namespace ebi
#line 2 "template/int_alias.hpp"

#line 4 "template/int_alias.hpp"

namespace ebi {

using ld = long double;
using std::size_t;
using i8 = std::int8_t;
using u8 = std::uint8_t;
using i16 = std::int16_t;
using u16 = std::uint16_t;
using i32 = std::int32_t;
using u32 = std::uint32_t;
using i64 = std::int64_t;
using u64 = std::uint64_t;
using i128 = __int128_t;
using u128 = __uint128_t;

}  // namespace ebi
#line 2 "template/io.hpp"

#line 5 "template/io.hpp"
#include <optional>
#line 7 "template/io.hpp"

namespace ebi {

template <typename T1, typename T2>
std::ostream &operator<<(std::ostream &os, const std::pair<T1, T2> &pa) {
    return os << pa.first << " " << pa.second;
}

template <typename T1, typename T2>
std::istream &operator>>(std::istream &os, std::pair<T1, T2> &pa) {
    return os >> pa.first >> pa.second;
}

template <typename T>
std::ostream &operator<<(std::ostream &os, const std::vector<T> &vec) {
    for (std::size_t i = 0; i < vec.size(); i++)
        os << vec[i] << (i + 1 == vec.size() ? "" : " ");
    return os;
}

template <typename T>
std::istream &operator>>(std::istream &os, std::vector<T> &vec) {
    for (T &e : vec) std::cin >> e;
    return os;
}

template <typename T>
std::ostream &operator<<(std::ostream &os, const std::optional<T> &opt) {
    if (opt) {
        os << opt.value();
    } else {
        os << "invalid value";
    }
    return os;
}

void fast_io() {
    std::cout << std::fixed << std::setprecision(15);
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);
}

}  // namespace ebi
#line 2 "template/utility.hpp"

#line 5 "template/utility.hpp"

#line 2 "graph/template.hpp"

#line 4 "graph/template.hpp"

namespace ebi {

template <class T> struct Edge {
    int to;
    T cost;
    Edge(int _to, T _cost = 1) : to(_to), cost(_cost) {}
};

template <class T> struct Graph : std::vector<std::vector<Edge<T>>> {
    using std::vector<std::vector<Edge<T>>>::vector;
    void add_edge(int u, int v, T w, bool directed = false) {
        (*this)[u].emplace_back(v, w);
        if (directed) return;
        (*this)[v].emplace_back(u, w);
    }
};

struct graph : std::vector<std::vector<int>> {
    using std::vector<std::vector<int>>::vector;
    void add_edge(int u, int v, bool directed = false) {
        (*this)[u].emplace_back(v);
        if (directed) return;
        (*this)[v].emplace_back(u);
    }
};

}  // namespace ebi
#line 8 "template/utility.hpp"

namespace ebi {

template <class T> inline bool chmin(T &a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

template <class T> inline bool chmax(T &a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template <class T> T safe_ceil(T a, T b) {
    if (a % b == 0)
        return a / b;
    else if (a >= 0)
        return (a / b) + 1;
    else
        return -((-a) / b);
}

template <class T> T safe_floor(T a, T b) {
    if (a % b == 0)
        return a / b;
    else if (a >= 0)
        return a / b;
    else
        return -((-a) / b) - 1;
}

constexpr i64 LNF = std::numeric_limits<i64>::max() / 4;

constexpr int INF = std::numeric_limits<int>::max() / 2;

const std::vector<int> dy = {1, 0, -1, 0, 1, 1, -1, -1};
const std::vector<int> dx = {0, 1, 0, -1, 1, -1, 1, -1};

}  // namespace ebi
#line 2 "data_structure/lazy_segtree.hpp"

/*
    reference:
   https://atcoder.github.io/ac-library/master/document_ja/lazysegtree.html
*/

#include <bit>
#line 11 "data_structure/lazy_segtree.hpp"
#include <ranges>
#line 13 "data_structure/lazy_segtree.hpp"

namespace ebi {

template <class S, S (*op)(S, S), S (*e)(), class F, S (*mapping)(F, S),
          F (*composition)(F, F), F (*id)()>
struct lazy_segtree {
  private:
    void update(int i) {
        data[i] = op(data[2 * i], data[2 * i + 1]);
    }

    void all_apply(int k, F f) {
        data[k] = mapping(f, data[k]);
        if (k < sz) lazy[k] = composition(f, lazy[k]);
    }

    void push(int i) {
        all_apply(2 * i, lazy[i]);
        all_apply(2 * i + 1, lazy[i]);
        lazy[i] = id();
    }

  public:
    lazy_segtree(int n_) : lazy_segtree(std::vector<S>(n_, e())) {}
    lazy_segtree(const std::vector<S> &a)
        : n(a.size()),
          sz(std::bit_ceil(a.size())),
          lg2(std::countr_zero(std::uint32_t(sz))) {
        data = std::vector<S>(2 * sz, e());
        lazy = std::vector<F>(sz, id());
        for (int i : std::views::iota(0, n)) {
            data[sz + i] = a[i];
        }
        for (int i : std::views::iota(1, sz) | std::views::reverse) {
            update(i);
        }
    }

    void set(int p, S x) {
        assert(0 <= p && p < n);
        p += sz;
        for (int i = lg2; i >= 1; i--) push(p >> i);
        data[p] = x;
        for (int i = 1; i <= lg2; i++) update(p >> i);
    }

    S get(int p) {
        assert(0 <= p && p < n);
        p += sz;
        for (int i = lg2; i >= 1; i--) push(p >> i);
        return data[p];
    }

    S prod(int l, int r) {
        assert(0 <= l && l <= r && r <= n);
        if (l == r) return e();

        l += sz;
        r += sz;

        for (int i = lg2; i >= 1; i--) {
            if (((l >> i) << i) != l) push(l >> i);
            if (((r >> i) << i) != r) push((r - 1) >> i);
        }

        S sml = e(), smr = e();
        while (l < r) {
            if (l & 1) sml = op(sml, data[l++]);
            if (r & 1) smr = op(data[--r], smr);
            l >>= 1;
            r >>= 1;
        }

        return op(sml, smr);
    }

    S all_prod() const {
        return data[1];
    }

    void apply(int p, F f) {
        assert(0 <= p && p < n);
        p += sz;
        for (int i = lg2; i >= 1; i--) push(p >> i);
        data[p] = mapping(f, data[p]);
        for (int i = 1; i <= lg2; i++) update(p >> i);
    }

    void apply(int l, int r, F f) {
        assert(0 <= l && l <= r && r <= n);
        l += sz;
        r += sz;
        for (int i = lg2; i >= 1; i--) {
            if (((l >> i) << i) != l) push(l >> i);
            if (((r >> i) << i) != r) push((r - 1) >> i);
        }

        {
            int memo_l = l, memo_r = r;
            while (l < r) {
                if (l & 1) all_apply(l++, f);
                if (r & 1) all_apply(--r, f);
                l >>= 1;
                r >>= 1;
            }
            l = memo_l;
            r = memo_r;
        }

        for (int i = 1; i <= lg2; i++) {
            if (((l >> i) << i) != l) update(l >> i);
            if (((r >> i) << i) != r) update((r - 1) >> i);
        }
    }

    template <class G> int max_right(int l, G g) {
        assert(0 <= l && l <= n);
        assert(g(e()));
        if (l == n) return n;
        l += sz;
        for (int i = lg2; i >= 1; i--) push(l >> i);
        S sm = e();
        do {
            while (l % 2 == 0) l >>= 1;
            if (!g(op(sm, data[l]))) {
                while (l < sz) {
                    push(l);
                    l = l << 1;
                    if (g(op(sm, data[l]))) {
                        sm = op(sm, data[l]);
                        l++;
                    }
                }
                return l - sz;
            }
            sm = op(sm, data[l]);
            l++;
        } while ((l & -l) != l);
        return n;
    }

    template <class G> int min_left(int r, G g) {
        assert(0 <= r && r <= n);
        assert(g(e()));
        if (r == 0) return 0;
        r += sz;
        for (int i = lg2; i >= 1; i--) push((r - 1) >> i);
        S sm = e();
        do {
            r--;
            while (r > 1 && r % 2) r >>= 1;
            if (!g(op(data[r], sm))) {
                while (r < sz) {
                    push(r);
                    r = (r << 1) + 1;
                    if (g(op(data[r], sm))) {
                        sm = op(data[r], sm);
                        r--;
                    }
                }
                return r + 1 - sz;
            }
            sm = op(data[r], sm);
        } while ((r & -r) != r);
        return 0;
    }

  private:
    int n, sz, lg2;
    std::vector<S> data;
    std::vector<F> lazy;
};

}  // namespace ebi
#line 3 "a.cpp"

#line 2 "modint/modint.hpp"

#line 5 "modint/modint.hpp"

#line 2 "modint/base.hpp"

#include <concepts>
#line 6 "modint/base.hpp"

namespace ebi {

template <class T>
concept Modint = requires(T a, T b) {
    a + b;
    a - b;
    a * b;
    a / b;
    a.inv();
    a.val();
    a.pow(std::declval<long long>());
    T::mod();
};

template <Modint mint> std::istream &operator>>(std::istream &os, mint &a) {
    long long x;
    os >> x;
    a = x;
    return os;
}

template <Modint mint>
std::ostream &operator<<(std::ostream &os, const mint &a) {
    return os << a.val();
}

}  // namespace ebi
#line 7 "modint/modint.hpp"

namespace ebi {

template <int m> struct static_modint {
  private:
    using modint = static_modint;

  public:
    static constexpr int mod() {
        return m;
    }

    static constexpr modint raw(int v) {
        modint x;
        x._v = v;
        return x;
    }

    constexpr static_modint() : _v(0) {}

    constexpr static_modint(long long v) {
        v %= (long long)umod();
        if (v < 0) v += (long long)umod();
        _v = (unsigned int)v;
    }

    constexpr unsigned int val() const {
        return _v;
    }

    constexpr unsigned int value() const {
        return val();
    }

    constexpr modint &operator++() {
        _v++;
        if (_v == umod()) _v = 0;
        return *this;
    }
    constexpr modint &operator--() {
        if (_v == 0) _v = umod();
        _v--;
        return *this;
    }

    constexpr modint operator++(int) {
        modint res = *this;
        ++*this;
        return res;
    }
    constexpr modint operator--(int) {
        modint res = *this;
        --*this;
        return res;
    }

    constexpr modint &operator+=(const modint &rhs) {
        _v += rhs._v;
        if (_v >= umod()) _v -= umod();
        return *this;
    }
    constexpr modint &operator-=(const modint &rhs) {
        _v -= rhs._v;
        if (_v >= umod()) _v += umod();
        return *this;
    }
    constexpr modint &operator*=(const modint &rhs) {
        unsigned long long x = _v;
        x *= rhs._v;
        _v = (unsigned int)(x % (unsigned long long)umod());
        return *this;
    }
    constexpr modint &operator/=(const modint &rhs) {
        return *this = *this * rhs.inv();
    }

    constexpr modint operator+() const {
        return *this;
    }
    constexpr modint operator-() const {
        return modint() - *this;
    }

    constexpr modint pow(long long n) const {
        assert(0 <= n);
        modint x = *this, res = 1;
        while (n) {
            if (n & 1) res *= x;
            x *= x;
            n >>= 1;
        }
        return res;
    }
    constexpr modint inv() const {
        assert(_v);
        return pow(umod() - 2);
    }

    friend modint operator+(const modint &lhs, const modint &rhs) {
        return modint(lhs) += rhs;
    }
    friend modint operator-(const modint &lhs, const modint &rhs) {
        return modint(lhs) -= rhs;
    }
    friend modint operator*(const modint &lhs, const modint &rhs) {
        return modint(lhs) *= rhs;
    }

    friend modint operator/(const modint &lhs, const modint &rhs) {
        return modint(lhs) /= rhs;
    }
    friend bool operator==(const modint &lhs, const modint &rhs) {
        return lhs.val() == rhs.val();
    }
    friend bool operator!=(const modint &lhs, const modint &rhs) {
        return !(lhs == rhs);
    }

  private:
    unsigned int _v = 0;

    static constexpr unsigned int umod() {
        return m;
    }
};

using modint998244353 = static_modint<998244353>;
using modint1000000007 = static_modint<1000000007>;

}  // namespace ebi
#line 5 "a.cpp"

namespace ebi {

using mint = modint998244353;

mint op(mint a, mint b) {
    return a + b;
}

mint e() {
    return 0;
}

mint mapping(mint f, mint x) {
    return f * x;
}

mint composition(mint f, mint g) {
    return f * g;
}

mint id() {
    return 1;
}

void main_() {
    int n,m;
    std::cin >> n >> m;
    std::vector<i64> xs(n);
    std::cin >> xs;
    std::map<i64, mint> map1, map2;
    lazy_segtree<mint, op, e, mint, mapping, composition, id> seg1(n+1), seg2(n+1);
    seg1.set(0, 1);
    seg2.set(0, 1);
    int r = 0;
    i64 sum = 0;
    mint inv_n = mint(n).inv();
    rep(i,0,n) {
        if(xs[i] == -1) {
            seg1.apply(0, r, m-1);
            seg2.apply(0, r, m-1);
            map1.clear();
            map2.clear();
            r = i + 1;
        }
        else {
            sum += xs[i];
            sum %= m;
        }
        mint ret1 = seg1.prod(0, r);
        mint ret2 = seg2.prod(0, r);
        if(xs[i] != -1) {
            ret1 += map1[sum];
            ret2 += map2[sum];
            map1[sum] += ret1;
            map2[sum] += ret2 - ret1 * inv_n;
        }
        seg1.set(i+1, ret1);
        seg2.set(i+1, ret2 - ret1 * inv_n);
    }
    mint ans = seg2.get(n) * n;
    std::cout << ans << '\n';
}

}  // namespace ebi

int main() {
    ebi::fast_io();
    int t = 1;
    std::cin >> t;
    while (t--) {
        ebi::main_();
    }
    return 0;
}